Non-equilibrium Transport in the Strange Metal and Pseudogap phases of the Cuprates

Abstract

We propose that the non-equilibrium current measured in the $a-b$ plane of an underdoped cuprate (in either the strange metal or pseudogap regime) in contact with either an overdoped cuprate or a standard Fermi liquid can be used diagnose how different the pseudogap and strange metals are from a Fermi liquid. Naively one expects the strange metal to be more different from a Fermi liquid than is the pseudogap. We compute the expected non-equilibrium transport signal with the three Green functions that are available in the literature: 1) marginal Fermi liquid theory, 2) the phenomenological ansatz for the pseudogap regime and 3) the Wilsonian reduction of the Hubbard model which contains both the strange metal and pseudogap. All three give linear IV curves at low bias voltages. Significant deviations from linearity at higher voltages obtain only in the marginal Fermi liquid approach. The key finding, however, is that IV curves for the strange metal/Fermi liquid contact that exceed that of the pseudogap/Fermi liquid system. If this is borne out experimentally, this implies that the strange metal is less orthogonal to a Fermi liquid than is the pseudogap. Within the Wilsonian reduction of the Hubbard model, this result is explained in terms of a composite-particle picture. Namely, the pseudogap corresponds to a confinement transition of the charge degrees of freedom present in the strange metal. In the strange metal the composite excitations break up and electron quasiparticles scatter off bosons. The bosons here, however, do not arise from phonons but from the charge degrees of freedom responsible for dynamical spectral weight transfer.

submitted to PRB

References in corpus (16)

• Magnetic order in the pseudogap phase of high-$T_C$ superconductors
• Polar Kerr Effect Measurements of YBa2Cu3O6+x: Evidence for Broken Symmetry Near the Pseudogap Temperature
• A Phenomenological Theory of The Pseudogap State
• Lifshitz critical point in the cuprate superconductor YBa2Cu3Oy from high-field Hall effect measurements
• Bounding the pseudogap with a line of phase transitions in YBCO cuprate superconductors
• Modeling the Fermi arc in underdoped cuprates
• Evidence for a Fermi liquid in the pseudogap phase of high-Tc cuprates
• Competition between spin density wave order and superconductivity in the underdoped cuprates
• Absence of Luttinger's Theorem due to Zeros in the Single-Particle Green Function
• Composite-Fermion Theory for Pseudogap, Fermi Arc, Hole Pocket, and Non-Fermi-Liquid of Underdoped Cuprate Superconductors
• Absence of static orbital current magnetism at the apical oxygen site in HgBa${}_2$CuO${}_{4+\delta }$ from NMR
• Hidden Charge 2e Boson in Doped Mott Insulators: Field Theory of Mottness
• Exact Integration of the High Energy Scale in Doped Mott Insulators
• Andreev and Single Particle Tunneling Spectroscopies in Underdoped Cuprates
• Universal inhomogeneous magnetic-field response in the normal state of cuprate high-Tc superconductors
• Nonequilibrium Green's-Function Approach to the Suppression of Rectification at Metal--Mott-Insulator Interfaces

Cited by in corpus (1)

• Recent Progress of Point Contact Spectroscopy as a Probe of Correlated Electron States